Cancer is the second most common cause of alcohol-related death in both men and women in Australia. In view of this and other health risks, mandatory health warnings on alcoholic beverages have been proposed in Australia and introduced elsewhere. This paper reviews academic literature and statements from selected advocacy groups to identify the ethical justifications that are used in relation to mandatory health warnings on alcoholic beverages. The paper then analyses how these justifications relate to the ethics of public health interventions in the context of cancer prevention. This involves examining the potential tension between the utilitarian nature of public health interventions and the liberalism characteristic of many of the societies in which those interventions occur.